title: Triple signal amplification using gold nanoparticles, bienzyme and platinum nanoparticles functionalized graphene as enhancers for simultaneous multiple electrochemical immunoassay.
abstract: Here we demonstrated an ultrasensitive electrochemical immunoassay employing graphene, platinum nanoparticles (PtNPs), glucose oxidase (GOD) and horseradish peroxidase (HRP) as enhancers to simultaneously detect carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP). This immunosensor is based on the observation that multiple-labeled antibodies (thionine-labeled anti-CEA and ferrocene-labeled anti-AFP) recognition event yielded a distinct voltammetric peak through "sandwich" immunoreaction, whose position and size reflected the identity and level of the corresponding antigen. Greatly enhanced sensitivity for cancer markers is based on a triple signal amplification strategy. Experimental results revealed that the immunoassay enabled simultaneous determination of CEA and AFP in a single run with wide working ranges of 0.01-100 ng mL(-1). The detection limits reached 1.64 pg mL(-1) for CEA and 1.33 pg mL(-1) for AFP. No obvious cross-talk was observed during the experiment. In addition, through the analysis of clinical serum samples, the proposed method received a good correlation with ELISA as a reference. The signal amplification strategy could be easily modified and extended to detect other multiple targets.
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China.
authors.forename: Xinle
authors.initials: X
authors.lastname: Jia
authors.forename: Xia
authors.initials: X
authors.lastname: Chen
authors.forename: Jingman
authors.initials: J
authors.lastname: Han
authors.forename: Jie
authors.initials: J
authors.lastname: Ma
authors.forename: Zhanfang
authors.initials: Z
authors.lastname: Ma
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002272:Carcinoembryonic Antigen / Q000737:chemistry / Q000302:isolation & purification*; D005949:Glucose Oxidase / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006108:Graphite; D006735:Horseradish Peroxidase / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry; D000509:alpha-Fetoproteins / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D002272:Carcinoembryonic Antigen; D000509:alpha-Fetoproteins; D010984:Platinum; D006046:Gold; D006108:Graphite; D005949:Glucose Oxidase; D006735:Horseradish Peroxidase
keywords: Electrochemical immunoassay; Graphene; Signal amplification; Simultaneous multianalyte detection; Tumor markers